Impact of an exercise program combined with dietary advice on avoiding insulin prescription in women with gestational diabetes: a randomized controlled trial.

Objective: To assess the effectiveness of an exercise intervention, in addition to standard care, in preventing or delaying insulin prescription in women with gestational diabetes mellitus (GDM).

Design: Randomised controlled trial.

Setting: University hospital.

Population: Pregnant women at 25-35 weeks of gestation diagnosed with GDM.

Methods: Women in the intervention group participated in weekly, supervised, 30-45 min exercise sessions and were encouraged to accumulate more than 5000 steps per day, tracked by a pedometer, in addition to receiving usual care. The control group received standard care only.

Main outcome measure: Insulin prescription.

Results: From February 2008 through April 2013, 109 women were randomized into the intervention group (n = 57) or the usual care group (n = 52). Two women in the intervention group were excluded from the analysis (one was randomised in error and one was lost to follow-up). Six women never attended the exercise sessions, and two attended fewer than two sessions. However, two-third of women were considered as compliant to the intervention (attended more than 50% of sessions and/or averaged more than 5000 steps/day). The incidence of insulin prescription did not differ between the groups: 31 women (56%) in the intervention group versus 24 women (46%) in the control group (RR 1.22, 95% CI 0.84 to 1.78). The median time from randomization to insulin prescription was also similar between groups (14 days in the intervention group and 13 days in the control group).

Conclusion: This study did not demonstrate that an exercise program reduces or delays insulin prescription in women with GDM. Low adherence to the intervention, a small sample size, and the short duration of the program may explain the lack of observed benefit.

Registered: At clinicaltrials.gov, NCT03174340, 02/06/2017.